ABSTRACT: The motive of this study was to investigate the interaction between polymorphisms in the MDR1 gene and anesthetic effects following pediatric tonsillectomy. In total, 240 children undergoing tonsillectomy with preoperative propofol-remifentanil anesthesia were selected. Genomic DNA was extracted from the peripheral blood of children after operation, and the MDR1 gene polymorphisms of 2677 G>T/A, 1236 C>T and 3435 C>T were detected by direct sequencing. We tested mean arterial pressure, diastolic blood pressure, systolic blood pressure, and heart rate at several time-points: T0 (5 mins after the repose), T1 (0?min after tracheal intubation), T2 (5 mins after the tracheal intubation), T3 (0?min after the tonsillectomy), T4 (0?min after removal of the mouth-gag) and T5 (5?min after the extubation). The visual analog scale, the face, legs, activity, cry, and consolability pain assessment, and the Ramsay sedation score were recorded after the patients regained consciousness. Adverse reactions were also recorded. The time of induction, respiration recovery, eye-opening, and extubation of children with the CC genotype were found to be shorter compared to the CT?+?TT genotype of MDR1 1236C?>?T (all P?<.05). The mean arterial pressure, diastolic blood pressure, systolic blood pressure, and heart rate were significantly reduced at T5 in children with the CC genotype (all P?<.05). The visual analog scale at 1, 2, 4, and 8?hours post-operation, and the Ramsay sedation score at 5, 10, and 30 min after the extubation were decreased, while the face, legs, activity, cry, and consolability pain assessment score increased (all P?<0.05). There was no statistically significant difference in the adverse reaction of MDR1 mutations (P> 0.05). It could be concluded that anesthetic effect following pediatric tonsillectomy in patients with the MDR1 1236C?>?T CC genotype was stronger than in those carrying the CT?+?TT genotype.
